Biofeedback Training

What is Biofeedback-Training?

In biofeedback training the objective is to measure certain body functions, that are normally not consciously perceivable, and to report these back to the patient. The patient can then learn to shift these measured signals in the desired direction by means of this feedback. Thus, for example, it can be learned to reduce muscle tension, increase hand temperature or to reduce the sweat gland activity in the hands.

Sometimes biofeedback is used to show the patient how the body reacts to specific pictures, words or situations. In a conversation, for example, certain stressors are addressed and it can be demonstrated how for example the skin conductance, the muscle tension or the heart rate increase significantly. On the other hand, during a relaxation exercise it can be observed that these values are shifted in the other direction. In biofeedback training it is practiced over several sessions to shift certain body functions in a therapeutically useful way in order to train the flexibility between different states and then to transfer the learned stategies into evryday life.

Neurofeedback-training is a special form of biofeedback, which trains the brain´s capacity for self-regulation. Because the electroencephalogram (EEG) is measured, some people call it EEG biofeedback. 

In the following it is described how the individual training sessions look like.

Preparation of the Training

First of all, the appropriate sensors must be attached to the patient.

For many biofeedback signals the sensors are attached on the hand. For example, with a ... the pulse at the finger is measured and from this signal the current heart rate is calculated. For measuring the skin conductivity two electrodes are fastened to the finger tips, where we have the highest density of sweat glands. A small temperature sensor on the finger can measure smallest changes in hand temperature.
If muscle activity is to be reported back, normally disposable adhesive electrodes are stuck to the corresponding muscle. This can be the shoulder-neck muscles, the forehead or the chewing muscles (masseter).
For the vasoconstriction training, that is often used to treat migraine patients, an optical sensor is placed on the temporal artery on the temple to measure changes in vessel width.

For neurofeedback training, normally 3-5 electrodes are attached to the skin with electrode gel.

The Actual Biofeedback Training

For the training, the patient sits in a comfortable chair in front of the patient screen and the therapist chooses an appropriate feedback option in order to direct the attention of the patient to the biosignal that has to be changed. Many different signals can be measured at the same time, but the patient normally gets to see only one or two of them, which he can concentrate on for the moment. 

In biofeedback often simple lines or bars are used in order to change the body signals.
Take for example a biofeedback training for relaxation: A physical relaxation response is accompanied by an increase in hand temperature because the muscles of the blood vessels relax and therefore more warm blood can flow from the body center to the extremeties. This can be measured as an increase in temperature. If a patient is supposed to learn such a reaction, this can be supported by a temperature biofeedback. The patient sees his current finger temperature displayed on the screen as a line graph, possibly combined with pleasant auditory feedback. If he manages to increase the finger temperature only very little - this is normally not perceivable - the line goes up and the tone pitch or volume change accordingly. The patient that does not feel anything on his hand yet, sees and hears through the feedback that the temperature has changed for the better and will continue in the same direction. 

As soon as the patient has learned to change his body signals by means of biofeedback the transfer excercises begin. This means, the feedback signal is hidden from the patient, for example the screen is turned off, and the patient is asked to repeat the same reaction without the feedback. Then the screen can be turned on again in order to see if he has succeeded without the feedback. For transfer to everyday life various strategies can be used. To stay with the temperature example, it can be helpful for some patients to imagine something warm, like sand in the sun, a hot shower, a camp fire or something similar.

This is the main difference between the peripheral biofeedback and neurofeedback for the patient. In modern Neurofeedback techniques strategies such as are sometimes used in biofeedback are not necessary, sometimes even counterproductive.

Completion of the Training

After the training session the sensors are removed and the therapist discusses the results of the session with his patient and how what has been learned can be transferred to everyday life. The patient is then instructed to watch for changes after the training carefully and to report these changes in the next session.